What will happen if it Rains?

At the drivers Press Conference in Singapore today Peter Windsor asked a very pertinent question:

My taxi driver said yesterday that he thought it was going to rain on Sunday - local opinion - and I just wondered that assuming you're not behind  a safety car and assuming that it is actually raining as distinct from damp, I just wondered what it might be like driving here under lights with falling rain at racing speeds

Bruno Senna and Sebastian Vettel made a stab at answering:

Senna:

I reckon the glare from the lights on the spray from the car in front can be quite difficult to cope with but we've never had that situation before so it's going to be a bit of a learning curve. We've driven in damp conditions (here) which is already fairly difficult on this track but with spray, I reckon it's going to be a very big challenge and we'll see if it's going to be possible or not. Hopefully it's going to be just like any other day in the wet.

Vettel:

Difficult to know, we've never driven in wet conditions here so we don't know how it will be with the lights. I think no one ever really drove a Formula One car at night during the rain with lights. I think it will be very slippery, because this circuit is not very grippy. I think it was a little bit damp at the beginning of practice last year so yeah, it will be slippery.

If Peter Windsor's taxi Driver is right Bruno could be right on in that glare from the lights in the spray from the car in front may well make it too dangerous to continue and force the race to be Red Flagged.